1. Field of the Invention
The invention relates to implant devices and instruments used to repair body tissue. In particular, the invention relates to an implant device, instruments and methods for repairing body tissue during endoscopic surgical procedures. Still more particularly, the invention relates to implant devices, instruments and methods for repairing meniscal tissue during arthroscopic surgery of the knee.
2. Description of the Prior Art
Implant devices for repairing body tissue are known in the prior art. While such devices may be classified into several categories, the present invention is related to elongated devices having transversely extending barbs or projections which assist in retaining the implant in place within a tissue defect (e.g. a tear) to hold body tissue in close approximation during the healing process.
One such known device is described in U.S. Pat. No. 4,873,976 (Schrieber). This device comprises a solid elongated shaft having a plurality of transversely extending projections, a pointed tip and a transverse circular head at its proximal end.
Other similar devices are disclosed in U.S. Pat. Nos. 4,884,572; 4,895,148; 4,924,865; and 4,976,715 all issued to Bays et al. The devices disclosed in these Bays et al. patents primarily differ from the Schrieber device in that they are cannulated. The Bays et al. patents are assigned to the assignee hereof and, along with Schrieber, are incorporated by reference herein.
All of the above described elongated devices are arrow-like and are designed to be inserted or pushed into tissue to be repaired. The devices are sometimes referred to as "tissue anchors" because they hold tissue together during healing. While these devices are intended to be used during arthroscopic or more generally endoscopic procedures, that very fact makes the insertion sometimes difficult. It is known to use elongated cannulas to guide the implants into position and smaller push rods to push them in. In the Schrieber type device, the implant is pushed through a cannula with an elongated pusher sized to be slidingly received within the cannula. With devices such as those disclosed in the Bays et al. patents the implant device is secured to the distal tip of a holding device and pushed into place, with or without the use of a guiding cannula.
All such arrow-like implant devices must not only enter tissue easily, but must resist migration once situated in place. Consequently, it is an object of this invention to provide a tissue anchor which has barbs to facilitate insertion and has a head design to minimize distal migration.
It is desirable to simplify the insertion process for these types of push-in arrow-like implant devices. It is also desirable to make such modifications to prior art arrow-like implant devices and systems as may improve their use and performance during and after (i.e. during healing when retention within tissue is important).
Accordingly, it is a further object of this invention to develop a tissue repair system incorporating a cannulated push-in implant or tissue anchor device, preferably bioabsorbable, and a simplified insertion apparatus, preferably operable by one hand.
It is also generally an object of this invention to provide a tissue anchor inserting device and method for guiding and inserting a cannulated tissue anchor into position at a surgical site.
It is another object of this invention to provide an elongated inserting device for receiving therein a cannulated tissue anchor, preferably at its distal end.
It is still another object of this invention to provide an elongated inserting device suitable for endoscopic procedures and capable of being operated from its proximal end.
It is also an object of this invention to provide a tissue anchor inserting system which facilitates the assembly of an inserting device with a cannulated tissue anchor.
It is yet another object of this invention to provide such a system with a holder for retaining a tissue anchor to facilitate such assembly.